The present invention is concerned with a loading mechanism for the upper rolls of a drafting zone used in textile processes in which the load on the upper rolls is created by using a pressurized cylinder. DE 38 14 340 A1 has placed into common knowledge a loading mechanism in which, to achieve sufficient pressure application onto the upper rolls, the pistons of the said loading mechanism possess a quadrilateral form. The minimal spatial distance of the loaded rolls at right angles to their respective axes should be held as small as possible. The pistons therein described require a membrane, in order to seal them off in relation to their cylinder wall.